In a widely available tilt-adjustable motor vehicle steering column, a bearing support or tilt housing is mounted on a stationary tubular mast jacket for up and down pivotal movement about a horizontal axis. A steering shaft assembly of the column includes an upper shaft rotatably supported on the tilt housing, a lower shaft rotatably supported on the mast jacket, and a universal joint therebetween. The universal joint includes bifurcated yokes on the upper and lower shafts and a plastic centering sphere between the yokes. Each of the yokes has frusto-conical bearing surfaces machined on opposite sides thereof which bearing surfaces seat in correspondingly shaped cross grooves in the centering sphere. The bearing surfaces slide relative to the sides of the cross grooves when the steering shaft assembly is rotated with the tilt housing articulated relative to the mast jacket. A steering shaft universal joint according to this invention is an improvement relative to the aforesaid universal joints having machined bearing surfaces.